It is very difficult to form a deep drawn contour in a laminate having a finish sheet, such as a self-supporting polymer backed carpet laminate, without stretching or tearing the carpet or finish sheet. Such laminates are used by the automotive industry for vehicle interior coverings, including deck lids, side and front panels, interior wheel covers for vans, center consoles and deep drawn door sills. The prior methods do not allow deep drawing of a carpet laminate, for example, particularly where the laminate must be drawn in more than one area, such as the ends of a deep drawn door sill.
One prior art method includes forming a plastic shell or substrate and then bonding the finish sheet over the contoured surfaces of the formed plastic substrate. This, of course, often results in poor bonding, gaps, mismatching, etc. It is also common to incorporate a manual positioning of the sheet stock in a die press, with or without a frame, and complex fixed frame assemblies have been utilized to reduce the stretching of the finish sheet in a die forming operation. These methods often result in stretching and tearing of the carpet or woven finish sheet, particularly where the laminate is deeply drawn by the die members.
The need therefore remains for a method of forming a permanently deep drawn contour in a sheet or panel, particularly a laminate having a woven finish sheet and a plastic substrate, such as a polymer backed carpet. The method of this invention is particularly suitable for forming deep drawn contours in such laminates, without tearing the carpet or finish sheet.